: . . . I'm looking at a small Kayak-like boat. . .

First look at www.gaboats.com. Platt Monfort designed boats which should cath your eye.

For a skin on frame boat you use very little material. If you NEED ash for stringers, spend $15 and get a board to rip into strips. It will be a bit more than bamboo, but it will work better.

Having said that, I applaud your idea to experiment with bamboo.
Don't be too surprised if the material is more complicated to use than you first expected.

Cane is a lovely material which goes as limp as cooked spaghetti when it gets saturated. Unless you completely seal it with epoxy, it WILL soak up water and when it gets damp enough it will lose its shape. If this is used for structural components, catastrophic failure will occur. Cane makes great seats, tho.

Historically bundles of cane were used for sail-powered barges. Even when wet the cane would float. Cane can be woven into watertight baskets. It swells as it soaks up water, so a tight weave gets tighter. Some boats were made with a 'skin' of woven cane over a wood or bone frame. A coating of pitch sealed or prevented small leaks. I don't knw of any successful use of cane for a frame. Persoonally, I'd have more faith in rolled tubes of paper saturated with epoxy.

For decades bamboo was the prime material for top-grade fishing poles. It was also the leading contender for 'cheapest' fishing pole. Currently it still is. Why the difference? Cheap poles used the bamboo 'straight'. What you get looks like a stalk of bamboo with a metal ferrule in the middle. Expensive bamboo poles, however, split the bamboo stalks, planed the pieces smooth, rejoined them in a smooth, piece with a gentle taper that was controlled by the rodmaker. They wound the rods with silk and sealed them with a good varnish or shellac. The result was a strong and very flexible fishing rod which was a fiber-reinforced composite material. Currently, bamboo strips are compressed with plastic resins to make planks which are used for flooring...more...